Description: Hands-free calling function provides greater safety while driving, clear and convenient tuning frequency adjustment. LCD 3,5 mm display displays frequency with blue backlight stereo sound, with touch key, high fidelity stereo. Powered by rechargeable built-in lithium battery, no need to use power. Universal: all devices with 3,5 mm headphone jack (all include 4 4S 5 5S 6), (all), S, S2, S3, S4 Specifications: Transmission Frequency: 87,5-108,0 (MHz) Effective range: 5-10M Voltage: 5 V USB car charger output: 5 V/ 1000 mA Degree of distortion: 2% Current: 30ma (FM) Frequency Response: 20-20kHz Left and right channels: 45 (dB) Black color Size: about 6X2 cm How to use: Turn it on by switching it to “ON”. Press “” or “-” on the device to select the frequency. radio frequency to the same frequency . Plug in the car charger and insert the car charger into the cigarette lighter socket to charge the battery. Music will be sent to your car system and played while charging. The package includes: 1 x 3,5 mm FM 1 USB cable